Automated Subfield Volumetric Analysis of Hippocampus in Patients with Drug-Naïve Nondementia Parkinson's Disease.

Jin-Woo Park,Chan-Nyoung Lee,Youngbo Sim,Hyung-Kyu Ham,Woo-Suk Tae,Byung-Jo Kim

doi:10.1155/2019/8254263

Abstract

Several studies used automated segmentation of hippocampal subfield (ASHS) for detailed measurements of anatomic subregions of the hippocampus, especially in the field of neurodegenerative disorders. In this study, we investigated the hippocampal subfield volume of patients with early-stage nondementia PD compared with normal healthy subjects using the ASHS method. A total of 32 subjects were enrolled in this study (sixteen patients with drug naive nondementia PD and sixteen healthy controls). All subjects were scanned with a 1.5 tesla MRI. The volumes of the seven subfields were calculated separately, and then, the whole hippocampal volume was calculated by the summing of CA1, CA2-3, CA4-DG, subiculum, presubiculum, and fimbria, excluding the hippocampal fissure. There were significant diagnosis-by-hemisphere interactive effects on the total hippocampal volume (F = 5.197; p=0.031) and the subfield volume of CA2-3 (F = 7.586; p=0.010) and CA4-DG (F = 7.403; p=0.011). The volumes of CA2-3 (F = 19.911; p < 0.001), CA4-DG (F = 20.273; p < 0.001), and total hippocampus (F = 10.573; p=0.005) in the left hemisphere were reduced compared to the right hemisphere. We suggest that the hippocampal volume asymmetry, especially in CA4-DG and CA2-3, could be observed in drug-naïve PD patients even in the early stage of the disease.

Highlights

Parkinson’s disease (PD) is one of the common neurodegenerative disorders, presenting with various clinical manifestations and heterogenous disease progression [1, 2].While F-18 FP-CIT PET imaging has been widely accepted as a standard tool for pathophysiologic evaluation of patients with PD, conventional MRI is less often used in clinical practice; especially in the early diagnosis of PD, its specificity and sensitivity are not satisfactory [3]
Our study highlighted that hippocampal asymmetry, especially in CA4-dentate gyrus (DG) and CA2-3, could be observed in patients with drug-naıve PD by using the automated segmentation of hippocampal subfield (ASHS) method. e CA4DG area appeared to be the most affected after false discovery rate (FDR) correction
Possible hippocampal atrophy in patients with nondementia PD has been discussed over many years, there was controversy over the issue [6, 7, 9, 15,16,17]

Summary

Introduction

Parkinson’s disease (PD) is one of the common neurodegenerative disorders, presenting with various clinical manifestations and heterogenous disease progression [1, 2].While F-18 FP-CIT PET imaging has been widely accepted as a standard tool for pathophysiologic evaluation of patients with PD, conventional MRI is less often used in clinical practice; especially in the early diagnosis of PD, its specificity and sensitivity are not satisfactory [3]. Recent studies revealed that analysis of MRI using voxelbased morphometry (VBM), functional MRI (fMRI), and diffusion tensor imaging (DTI) provides potentially useful information regarding disease progression [3, 4]. Several studies used automated segmentation of hippocampal subfield (ASHS) for detailed measurements of anatomic subregions of the hippocampus, especially in the field of neurodegenerative disorders including PD [5,6,7]. Ese studies suggested that the changes in the hippocampal subfields could be associated with cognitive functions and could be used as informative diagnostic biomarkers for PD dementia (PDD) and PD with mild cognitive impairment (PD-MCI) [6,7,8].

Methods

Results

Conclusion